Max temp of pipes near extruded polystyrene?

johncharles

Planning to build a chase through an outdoor porch along the side of the house to run supply and return for some baseboard in a room above. I was planning on using 2” XPS on the three exterior facing sides, but could not find the maximum safe temperature for XPS. Will the 180* pipe temperature be too hot for it?

pecmsg

165°F

2" is not a lot of insulation value.

What's the insulation on the floor of this Room Above?

johncharles

My figuring is that one side is facing into the house, so should have a mild heat source coming through the wall of the house, how much insulation around the pipe would be sufficient?

hot_rod

1" wall pipe insulation, the rubber type, not the foam. Insulate the pipes first for a good tight seal.

I would think the chase would insulate like the walls of your home? 4, 6 or more insulation if you can. Fiberglass batts are inexpensive r value compared to foam.

Foam is around R-5 per inch, depending on the type. So two inches is R-10. A 6" fiberglass batt is R-19, almost twice what the foam would give you.